storage: Add bls_boot_binaries_dir method

For grub booted systems, we keep Type1 (BLS) boot binaries (kernel +
initrd) in `/sysroot/boot`, which is also where `Storage::boot_dir`
points to. But, for systems with systemd-boot as the bootloader, we keep
the said binaries at `ESP/EFI/Linux` but `Storage::boot_dir` points at
the ESP

This function opens the proper directory depending on the bootloader. We
need this primarily for GC

Signed-off-by: Pragyan Poudyal <pragyanpoudyal41999@gmail.com>

Author: Johan-Liebert1

crates/lib/src/bootc_composefs/gc.rs

@@ -10,9 +10,8 @@ use composefs::repository::GcResult;
 use composefs_boot::bootloader::{EFI_ADDON_DIR_EXT, EFI_EXT};
 
 use crate::{
-    bootc_composefs::boot::get_type1_dir_name,
     bootc_composefs::{
-        boot::{BOOTC_UKI_DIR, BootType},
+        boot::{BOOTC_UKI_DIR, BootType, get_type1_dir_name},
         delete::{delete_image, delete_staged, delete_state_dir},
         status::{get_composefs_status, get_imginfo, list_bootloader_entries},
     },
@@ -66,7 +65,7 @@ type BootBinary = (BootType, String);
 #[fn_error_context::context("Collecting boot binaries")]
 fn collect_boot_binaries(storage: &Storage) -> Result<Vec<BootBinary>> {
     let mut boot_binaries = Vec::new();
-    let boot_dir = storage.require_boot_dir()?;
+    let boot_dir = storage.bls_boot_binaries_dir()?;
     let esp = storage.require_esp()?;
 
     // Scan for UKI binaries in EFI/Linux/bootc
@@ -125,14 +124,14 @@ fn collect_type1_boot_binaries(boot_dir: &Dir, boot_binaries: &mut Vec<BootBinar
 
 #[fn_error_context::context("Deleting kernel and initrd")]
 fn delete_kernel_initrd(storage: &Storage, dir_to_delete: &str, dry_run: bool) -> Result<()> {
-    let boot_dir = storage.require_boot_dir()?;
-
     tracing::debug!("Deleting Type1 entry {dir_to_delete}");
 
     if dry_run {
         return Ok(());
     }
 
+    let boot_dir = storage.bls_boot_binaries_dir()?;
+
     boot_dir
         .remove_dir_all(dir_to_delete)
         .with_context(|| anyhow::anyhow!("Deleting {dir_to_delete}"))
@@ -217,6 +216,7 @@ pub(crate) async fn composefs_gc(
     let boot_binaries = collect_boot_binaries(storage)?;
 
     tracing::debug!("bootloader_entries: {bootloader_entries:?}");
+    tracing::debug!("boot_binaries: {boot_binaries:?}");
 
     // Bootloader entry is deleted, but the binary (UKI/kernel+initrd) still exists
     let unreferenced_boot_binaries = boot_binaries

crates/lib/src/store/mod.rs

@@ -36,7 +36,7 @@ use ostree_ext::sysroot::SysrootLock;
 use ostree_ext::{gio, ostree};
 use rustix::fs::Mode;
 
-use crate::bootc_composefs::boot::mount_esp;
+use crate::bootc_composefs::boot::{EFI_LINUX, mount_esp};
 use crate::bootc_composefs::status::{ComposefsCmdline, composefs_booted, get_bootloader};
 use crate::lsm;
 use crate::podstorage::CStorage;
@@ -376,6 +376,28 @@ impl Storage {
             .ok_or_else(|| anyhow::anyhow!("ESP not found"))
     }
 
+    /// Returns the Directory where the Type1 boot binaries are stored
+    /// `/sysroot/boot` for Grub, and ESP/EFI/Linux for systemd-boot
+    pub(crate) fn bls_boot_binaries_dir(&self) -> Result<Dir> {
+        let boot_dir = self.require_boot_dir()?;
+
+        // boot dir in case of systemd-boot points to the ESP, but we store
+        // the actual binaries inside ESP/EFI/Linux
+        let boot_dir = match get_bootloader()? {
+            Bootloader::Grub => boot_dir.try_clone()?,
+            Bootloader::Systemd => {
+                let boot_dir = boot_dir
+                    .open_dir(EFI_LINUX)
+                    .with_context(|| format!("Opening {EFI_LINUX}"))?;
+
+                boot_dir
+            }
+            Bootloader::None => anyhow::bail!("Unknown bootloader"),
+        };
+
+        Ok(boot_dir)
+    }
+
     /// Access the underlying ostree repository
     pub(crate) fn get_ostree(&self) -> Result<&SysrootLock> {
         self.ostree